To reduce such problems, it is known to protect phosphors with silicon dioxide layers, which can be applied to the phosphor particles by hydrolysis of tetraethoxysilane (TEOS) in liquid solution, for example. Another possibility is the deposition of a coating material by means of chemical vapor deposition (CVD). However, such methods are very time-consuming and costly, as separate chemicals have to be provided for the vapor deposition or the deposition of a silicon dioxide layer.
The production of a protective layer on a phosphor particle is known from US application US 2006/0263627, wherein large quantities of acid are added to form a coating. However, this method can easily lead to the disintegration of a large proportion of the phosphor, as a large quantity of acid is normally added.
The subject matter of the present invention consists in providing a method for the production of phosphor particles of an Si-containing and/or Al-containing phosphor with a protective layer and in providing an Si-containing and/or Al-containing phosphor with a protective layer, which is improved with reference to the aforesaid technical problems.
Advantageous configurations of the method for the production of the phosphor particles and advantageous configurations of the novel phosphor particles with the protective layer are the subject of further dependent claims.